1. Field of the Invention
This invention relates to a socket for the writing ball of a ball point pen and more particularly to a socket for the writing ball of a ball point pen provided with a very easily formed ink passage for conducting aqueous ink from the ink cartridge to the writing ball of the ball point pen.
2. Description of the Prior Art:
A socket for the writing ball of the prior art ball point pen comprises a tubular member, a writing ball held in the forward end portion of the tubular member, a ball-bearing rod of circular cross section inserted into the tubular member with a recessed seat provided at the forward end of the rod to receive the writing ball, and an ink passage consisting of a groove formed along the full length of the ball-bearing rod. However, the socket of the prior art ball point pen has the drawbacks that since the ball-bearing rod is made of sufficiently hard metal to be saved from abrasion by the rotation of the writing ball, considerable difficulties are presented in machining an ink passage in the ball-bearing rod, resulting in high working cost.
It is accordingly the object of this invention to provide a socket for a ball point pen which includes an inner metal tubular member, enabling an ink passage to be very easily provided without machining an abrasion-resistant ball-bearing rod.